Please help its due in 2 mins

Approximately what wavelength of light is best absorbed by chlorophyll a

You and a group of friends are spending your vacation hiking through the mountains. it is cold in the mountains. you will be expending a lot of energy while hiking and you will need plenty of energy to keep you warm. you should pack foods high in to provide the most energy or kilocalories per gram of food. a) carbohydrates b) lipids (fats) c) proteins d) sugars

Why do mountaineers become breathless as they reach high altitudes